KR101445201B1 - Motor control device, and air conditioner using the same - Google Patents

Abstract

When the number of PWM pulses is constant and the number of revolutions of the motor becomes high, the number of PWM pulses included in one cycle of voltage and current becomes smaller than that in the low speed range. Therefore, the present invention aims to prevent a situation in which a high-order component can not be output, and consequently a current waveform is distorted.
In order to solve the above problems, a motor drive apparatus of the present invention includes: a power converter for driving a permanent magnet motor; a control device for controlling an output voltage of the power converter; The higher the number of revolutions of the permanent magnet motor, the smaller the degree of the higher-order component of the induced voltage added to the voltage command value of the control device.

Description

TECHNICAL FIELD [0001] The present invention relates to a motor control device and an air conditioner using the same,

TECHNICAL FIELD The present invention relates to a control method of a motor control apparatus and an apparatus using the same, particularly to suppression of current pulsation.

The motors used in air conditioners are strongly demanded for miniaturization, high efficiency, and high output.

(Hereinafter referred to as " IPM motor ") in which a permanent magnet is embedded in a rotor of a motor by concentrically winding the motor stator side, .

However, the waveform of the induced voltage induced in the winding of the IPM motor becomes a distorted waveform from the ideal sinusoidal shape with respect to the angle of the rotor of the IPM motor. Distortion occurs in the current waveform due to distortion of the induced voltage waveform.

Patent Document 1 discloses a technique for extracting a periodic component of motor rotational speed variation using a resonant filter and correcting a torque current command value based on a periodic component of fluctuation. According to Patent Document 1, it is possible to suppress fluctuation in the number of revolutions caused by distortion of the induced voltage waveform.

Patent Document 2 discloses a technique of calculating a harmonic current command that causes a torque in a phase opposite to that of a torque ripple of a motor and controlling the harmonic current. According to Patent Document 2, the fluctuation of the motor torque can be reduced.

Japanese Patent Application Laid-Open No. 2006-191737 Japanese Patent Application Laid-Open No. 2004-64909

According to the technique described in Patent Document 1, ideally all the higher-order components included in the induced voltage of the motor can be output. However, since the number of PWM pulses is a finite value, practically all the higher- Can not be output.

In particular, when the number of PWM pulses is constant and the number of revolutions of the motor becomes high, the number of PWM pulses included in one cycle of voltage and current becomes smaller than that in the low speed range.

The technique described in Patent Document 2 outputs a harmonic current command that causes a torque in a phase opposite to that of the torque ripple, so that distortion occurs in the current waveform.

Therefore, the present invention aims to prevent a situation in which a high-order component can not be output, and consequently a current waveform is distorted.

In order to solve the above problems, a motor drive apparatus of the present invention includes: a power converter for supplying power to a permanent magnet motor; a control device for controlling an output voltage of the power converter; The higher the number of revolutions of the permanent magnet motor, the smaller the degree of the higher-order component of the induced voltage added to the voltage command value of the control device.

According to the present invention, it is possible to prevent a situation in which a high-order component can not be outputted and the current waveform is distorted inversely.

1 is a block diagram showing an overall configuration of a motor control apparatus according to a first embodiment;
FIG. 2 is a schematic diagram showing the relationship between an induced voltage, a command voltage, and a motor current at fixed coordinates in the case of a sinusoidal file in which an induced voltage waveform is ideal; FIG.
3 is a schematic diagram showing a relationship between an induced voltage, a command voltage, and a motor current in a fixed coordinate system in a conventional system when an induced voltage waveform is distorted;
4 is a schematic diagram showing a relationship between an induced voltage, a command voltage, and a motor current at a rotational coordinate in the case of a sinusoidal file in which an induced voltage waveform is ideal;
5 is a schematic diagram showing a relationship between an induced voltage, a command voltage, and a motor current in a rotational coordinate system according to a conventional method when the induced voltage waveform is distorted.
6 is a schematic diagram showing a relationship between an induced voltage, a command voltage, and a motor current at fixed coordinates in the method of the first embodiment when the induced voltage waveform is distorted;
FIG. 7 is a schematic diagram showing the relationship between an induced voltage, a command voltage, and a motor current at a rotational coordinate in the method of the first embodiment when the induced voltage waveform is distorted; FIG.
FIG. 8 is an example of waveforms and FFT analysis of a U phase current when a real machine is driven by a conventional method.
FIG. 9 is an example of waveforms and FFT analysis of a U phase current when a real machine is driven by the method of the first embodiment; FIG.
Fig. 10 is a schematic diagram comparing a total loss when a real machine is driven by the conventional system and the system of the embodiment 1. Fig.
11 is a block diagram showing the overall configuration of a conventional motor control apparatus of PWM control system.
12 is a block diagram for adding an induced voltage higher-order component to an applied voltage command on a dq axis as a rotation coordinate system.
13 is a block diagram for adding an induced voltage higher-order component to an applied voltage command of three-phase alternating current.
14 is a diagram showing an example of setting an amplitude value of an induced voltage higher-order component;
Fig. 15 is a diagram showing an example of switching setting of an organic voltage higher-order component amplitude value; Fig.
16 is a diagram showing an example of switching setting of the PWM frequency in the second embodiment;
17 is an overall configuration view of an air conditioner using a motor control device.
18 is a schematic diagram of efficiency and DC voltage / applied voltage command for the motor rotational speed of the compressor motor.
Fig. 19 is an overall configuration diagram of a DC voltage boosting device applied to an air conditioner in accordance with the third embodiment; Fig.
20 is a schematic diagram of efficiency and DC voltage / applied voltage command of the motor for the compressor according to the third embodiment with respect to the number of revolutions of the motor;

Hereinafter, an embodiment of the present invention will be described.

[Example 1]

Embodiment 1 of the present invention will be described.

This embodiment applies the control method of the present invention to a motor control device for driving a permanent magnet synchronous motor (hereinafter referred to as " motor ") 3 by PWM control, Will be described below

First, the circuit configuration will be described with reference to Fig. The motor control device 1 includes a power conversion circuit 4 for converting DC power into AC power, a DC bus current detection circuit 5 for detecting a DC bus current flowing in the power conversion circuit 4, And a control device 6 for performing vector control on the basis of the DC bus current information 5A detected by the current detection circuit 5. [

The control device 6 includes a vector control unit 8, an organic voltage higher-order component generation unit 9, a voltage addition unit 10, and a PWM pulse generation unit 7.

The vector control unit 8 controls the basic wave applying voltage command 8B to the permanent magnet synchronous motor 3 based on the direct current bus line current information 5A detected by the direct current bus line current detecting circuit 5, The motor rotation number / phase information 8A of the motor 3 is calculated.

The induced voltage higher-order component generation section 9 outputs the induced voltage higher-order component 9A of the permanent magnet synchronous motor 3 to the voltage addition section 10 based on the motor revolution number / phase information 8A.

The voltage addition section 10 adds the organic voltage higher-order component 9A to the basic-wave applying voltage instruction 8B and outputs the applied voltage instruction 10A.

The PWM pulse generating section 7 converts the PWM pulse signal 7A based on the applied voltage command 10A and the carrier signal.

The power conversion circuit 4 includes a power conversion main circuit 41 constituted by a semiconductor switching element such as an IGBT and a diode and a power conversion main circuit 41 for generating a PWM pulse signal 7A from the PWM pulse generation section 7, And a gate driver 42 for generating a gate signal to the IGBT.

On the other hand, the acquisition of the phase current information by the DC bus current detection circuit 5 can use a general method and does not specify the detection method. The vector control unit 8 can be realized by using general vector control such as the method proposed in Patent Document 1, and does not specify the control method.

A vector control for controlling the current waveform in the sinusoidal waveform by the current controller will be described with reference to Figs. 2 to 5 and 11. Fig.

In Fig. 11, the same reference numerals as in Fig. 1 have the same functions. In the control device 60, the vector control unit 8 performs calculation based on the phase current information reproduced from the DC bus current information 5A.

Next, the relationship between the induced voltage waveform and the voltage / current will be described with reference to Figs. 2 to 5. Fig. Fig. 2 shows waveforms in a fixed coordinate system in a sinusoidal waveform in which the induced voltage waveform is ideal. Fig. 4 shows waveforms in a rotational coordinate system with reference to the magnetic flux of the permanent magnet in a sinusoidal waveform in which the induced voltage waveform is ideal. 2 (b) and 4 (b) show the applied voltage command. Fig. 2 (c) and Fig. 4 (c) Current.

3 shows waveforms in the fixed coordinate system when the induced voltage waveform is distorted. 5 shows the waveforms in the fixed coordinate system and the rotating coordinate system when the induced voltage waveform is distorted. 3 (a) and 5 (a) show the induced voltage, and FIG. 3 (b) and FIG. 5 Current.

When the induced voltage waveform of the permanent magnet synchronous motor is an ideal sinusoidal waveform, as shown in Figs. 2B and 2C, in the fixed coordinate system, the applied voltage command and the motor current have sinusoidal waveforms. 4 (b) and 4 (c), the applied voltage command and the motor current become constant values in the rotary coordinate system.

On the other hand, when the induced voltage waveform is distorted from the sinusoidal waveform, the motor current waveform is distorted due to these distortions, and vibration and noise are generated and efficiency is lowered.

The vector control unit 8 of the control device 60 outputs the phase current information as feedback so that the motor current becomes a sinusoidal wave form even when the induced voltage waveform is distorted as shown in Fig. 3 (b) and Fig. 5 Thereby controlling the voltage command value.

However, in order to increase the control period of the current controller and increase the responsiveness of the control, there is a limit due to the computing ability of the microcomputer. Therefore, when a motor having a large distortion of the induced voltage waveform is driven, the influence of the distortion of the induced voltage appearing in the motor current by the current controller can not be sufficiently reduced. As shown in Figs. 3C and 5C, Distortion occurs in the motor current waveform as shown.

Next, the control for suppressing the distortion of the current waveform caused by the distortion of the induced voltage waveform will be described with reference to Figs. 6 to 10. Fig.

The organic voltage higher-order component generating section 9 generates an induced voltage higher-order component based on the motor revolution number / phase information 8A using the previously obtained induced voltage waveform, (10).

The organic voltage higher-order component 9A output by the organic voltage higher-degree component generation section 9 is generated by using data obtained by tabulating the organic voltage waveform based on the waveform of the induced voltage previously determined by experiment or analysis. Here, even in the case of driving as the motor control device, it is also possible to generate and correct the induced voltage higher-order component 9A by acquiring the inter-terminal voltage at the time of motor revolution, for example.

The voltage adding unit 10 adds the basic wave applying voltage command 8B outputted by the vector control unit 8 and the organic voltage higher-order component 9A outputted by the organic voltage higher-degree-of-component generating unit 9, And outputs it to the generation unit 7. More specifically, as shown in Fig. 12, the induced voltage higher-order components 9A-1 and 8B-q are applied to the fundamental wave applying voltage commands 8B-d and 8B-q on the dq coordinate axes, which are rotational coordinate systems based on the magnetic flux direction of the motor rotor, d, 9A-q), it is possible to add the organic voltage higher-order component to the applied voltage command.

13, a method of adding the organic voltage higher-order components 9A-U, 9A-V and 9A-W to the three-phase alternating current command voltages 8B-U, 8B-V and 8B-W of the fixed coordinate system .

Here, Fig. 6 shows a schematic waveform in the fixed coordinate system when the organic voltage higher-order component is added to the applied voltage. Fig. 7 shows a schematic waveform in the rotational coordinate system when the organic voltage higher-order component is added to the applied voltage.

As shown in Figs. 6A and 7A, in this method, the higher-order component of the induced voltage waveform distortion is added to the fundamental wave applied voltage instruction 8B as the induced voltage higher-order component 9A. Therefore, as shown in Figs. 6 (b) and 7 (b), a voltage to which the organic voltage higher-order component 9A is applied is output to the applied voltage command 10A. Thus, as shown in Figs. 6C and 7C, the distortion of the current waveform due to the induced voltage waveform distortion can be reduced.

As described above, the induced voltage higher-level component generation section 9 generates the induced voltage higher-order component 9A, and the voltage addition section 10 adds the induced voltage higher-level component 9A to the base-wave applied voltage instruction 8B . In other words, the higher-order component included in the output voltage of the power conversion circuit 4 outputs a waveform similar to the motor induced voltage higher-order component. Therefore, distortion of the current waveform caused by the distortion of the induced voltage waveform can be suppressed by the induced voltage higher-order component generation section 9 and the voltage addition section 10. [

On the other hand, when displacement is applied to the current detection unit, the technique of Patent Document 1 generates the output voltage higher-order component from the current detection information, and therefore, the output voltage higher-order component changes. On the other hand, the technique of this embodiment can output a waveform similar to the motor induced voltage higher-order component as described above without affecting the change of the output voltage higher-order component, even when displacement is applied to the current detection unit.

Further, the higher-order component included in the output voltage of the power conversion circuit 4 does not need to completely overlap with the motor induced voltage higher-order component, and distortion of the current waveform can be reduced in a similar waveform.

In fact, since the total order of the organic voltage higher-order component 9A can not be applied to the fundamental-wave applying voltage instruction 8B, only the specific-order component is included.

Figs. 8 and 9 show the current waveforms when the actual voltage is added by adding the fifth-order component and the seventh-order component of the organic voltage higher-order component to the command voltage. Fig. 8 shows waveforms in a conventional control system not adding the organic voltage higher-order component, and Fig. 9 shows waveforms in the control system of this embodiment in which the organic voltage higher-degree component is added.

Figures 8 (a) and 9 (a) show the current on the U side of the motor 3. 8 (b) and 9 (b) show FFT analysis results of the current waveform on U with the fundamental wave component as 100%.

As shown in Figs. 8A and 8B, when the organic voltage higher-order component is not added, the current waveform is distorted due to the influence of the distortion of the induced voltage, and the fifth- It can be confirmed that the components are largely generated.

On the other hand, as shown in Figs. 9A and 9B, when the induced voltage higher-order component is added to the command voltage by the method of this embodiment, the distortion of the motor current waveform is suppressed, It can be confirmed that the current higher-order component of the seventh order can be reduced.

10 is a graph showing the relationship between the total loss of the power conversion circuit and the loss of the motor when the induced voltage component is not applied to the command voltage, Lt; / RTI > As shown in Fig. 10, by adding the organic voltage higher-order component to the command voltage and suppressing the current higher-order component, the total loss can be reduced.

As described above, according to the present embodiment, the high-order component of the motor current can be suppressed. In other words, even when the motor induced voltage is distorted, the high-order component of the motor current can be suppressed. By suppressing the higher-order component of the motor current, it is possible to suppress the output-power higher-order component of the power converter due to the current higher-order component, thereby achieving high efficiency of the motor control device.

Here, as an example of a method of adding the organic voltage higher-order component 9A to the fundamental-wave applying voltage instruction 8B with reference to Fig. 14, a method of switching the organic voltage higher-order component 9A according to the operating condition will be described . Ideally, by outputting all higher-order components included in the induced voltage of the motor as the induced voltage higher-order component 9A, it becomes possible to suppress the current higher-order component. However, when the number of PWM pulses is constant and the number of revolutions of the motor becomes a high speed, the number of PWM pulses included in one cycle of voltage and current is smaller than that of low speed, so that output of a component having a large degree of the induced voltage higher order component becomes difficult.

Thus, as shown in Fig. 14, the output of the component having a large order is stopped by the rotational speed of the motor 3 from the induced voltage higher-degree component generating section 9. [ Here, the outputs of the organic voltage 3, 5, 7, 9, 11, 13 components are switched in accordance with the number of revolutions of the motor 3.

14 (c), when the number of revolutions of the motor 3 is accelerated to be equal to or greater than the number of revolutions N1, the amplitude value of the 9 · 11 · 13th order component having a large degree is set to 0, And stops the output from the generator 9.

14 (b), when the number of revolutions of the motor becomes N2 or more, the amplitude value of the fifth-order / seventh-order component is set to O and the output from the organic voltage higher-degree-of-component generating section 9 is stopped.

In other words, when the number of revolutions is N2 or less, the induced voltage higher-order component output from the induced voltage higher-level component generator 9 includes components of 3, 5, 7, 9, 11, At revolutions N1 to N2, the induced voltage higher-order component output from the induced voltage higher-level component generator 9 includes the components of the 3 · 5 · 7 order. When the number of revolutions is N2 or more, the induced voltage higher-order component output from the induced voltage higher-level component generator 9 includes a tertiary component.

On the other hand, in order to suppress the fluctuation of the current, the number of revolutions, and the torque at the time of switching, the amplitude of the organic voltage higher-order component is changed from the number of revolutions N4 to the number of revolutions N5 at a constant rate as shown in Fig. do.

15 (c), the amplitude of the organic voltage higher-order component may be changed from the number of revolutions N4 to the number of revolutions N5 while changing the ratio as shown by a curve.

The amplitude value may be switched by using the output torque of the motor 3 or the DC bus current information 5A.

Thus, when the number of revolutions of the motor is high, the number of PWM pulses included in one cycle of voltage and current is smaller than that in the low speed region. Therefore, a high-order component can not be output by adding an organic voltage higher-order component having a large number of PWM pulses and a low order to the command voltage in one period, and it is possible to prevent the current waveform from being distorted.

On the other hand, when the number of revolutions of the motor is in the low-speed range, the distortion of the current waveform can be suppressed by adding the command voltage to the induced voltage higher-order component having a large number of PWM pulses and a low degree in one period.

On the other hand, in the present embodiment, the three-stage switching is described as shown in Fig. 14, but the present invention is not limited to this.

17 and 18, an example in which the motor control device 1 of the present embodiment is applied to driving the compressor of the air conditioner 100 will be described.

17, the air conditioner 100 of the present embodiment includes an outdoor unit 101 for performing heat exchange with outdoor air, an indoor unit 102 for performing heat exchange with the indoor unit, and a pipe 103 for connecting the indoor unit 102 and the indoor unit. The outdoor unit 101 includes a compressor 104 for compressing the refrigerant, a compressor drive motor 105 for driving the compressor 104, a motor control unit 1 for controlling the compressor 104, and a heat exchanger 107). The indoor unit 102 is composed of a heat exchanger 108 for performing heat exchange with the room and an air blower 109 for blowing air into the room.

Here, the efficiency of the compressor drive motor 105 and the DC voltage / applied voltage command will be described with reference to Fig. 18 (a), the axis of abscissas indicates the number of revolutions of the compressor drive motor 105, and the axis of ordinates indicates the efficiency of the compressor drive motor 105. In Fig. 18B, the axis of abscissas indicates the number of revolutions of the compressor drive motor 105, and the axis of ordinates indicates amplitude values of the DC voltage supplied to the power conversion circuit 4 and the applied voltage command.

When the DC voltage is constant and the PWM control is used, as shown in Fig. 18 (b), the amplitude value of the applied voltage command becomes a voltage saturation region above the DC voltage at the number of revolutions N9 or more. In the voltage saturation region, since the applied voltage command amplitude value becomes saturated and can not be controlled, the desired high voltage component 9A can not be output from the power conversion circuit 4. [

Therefore, in order to eliminate the influence of addition of the organic voltage higher-order component, the output from the organic voltage higher-degree component generator 9 is stopped, and the drive is performed by switching to normal PWM control.

By reducing the power high-order component of the power conversion circuit 4 as described above, efficiency can be improved in the region of lower speed than the rotation speed N9 at which the efficiency becomes the peak as shown by the dotted broken line in Fig. 18 (a) . The power high-order component of the power conversion circuit can be reduced by the same power conversion circuit configuration as that of the conventional motor control apparatus, and it becomes possible to perform the high efficiency of the air conditioner without adding any components.

[Example 2]

A second embodiment in which the PWM frequency for driving the power conversion circuit 4 is changed will be described with reference to Fig. Since the circuit configuration is the same as that of the motor control apparatus 1 shown in Fig. 1, a description thereof will be omitted.

As described above, when the number of PWM pulses is constant and the number of rotations of the motor becomes high, the number of PWM pulses included in one cycle of voltage and current becomes smaller than that in the low speed range. And it becomes difficult to output from the circuit 4.

Thus, in the second embodiment, as shown in Fig. 16, the PWM frequency is changed in accordance with the number of revolutions of the motor. Here, the PWM frequency is switched to f1 and f2 according to the number of rotations. As shown in Fig. 16 (a), when the number of rotations of the motor is increased and the number of rotations becomes N6 or more, the PWM frequency is switched from f2 to f1. Figs. 16B and 16C are modifications of the frequency changing method. Fig.

By changing the PWM frequency in accordance with the number of revolutions of the motor, the PWM frequency is increased in the high-speed range to keep the number of PWM pulses included in one cycle of voltage and current, and output of components having a large degree of the organic voltage higher- It becomes.

Further, by reducing the PWM frequency in the low-speed range, the switching loss can be reduced and the motor control apparatus 1 can be made more efficient.

On the other hand, a method of changing the PWM frequency described in the present embodiment and a method of changing the order of the organic voltage higher-order components added to the command voltage described in Embodiment 1 may be combined according to the number of motor rotations. By combining these two schemes, it is possible to compare the increase in the switching loss due to the increase in the PWM frequency and the decrease in the efficiency due to the distortion of the current waveform due to the output of the component having the higher order of the organic voltage higher- , The order of the PWM frequency and the high voltage component of the induced voltage can be selected. For example, when the increase in the switching loss is larger than the efficiency improvement effect due to the suppression of the distortion of the current waveform, the output of the component having a large degree of the organic voltage higher order component is not performed, thereby improving the overall efficiency .

In the present embodiment, the two-stage switching is described as shown in Fig. 16, but the present invention is not limited to this.

[Example 3]

19 and 20, a third embodiment in which the DC voltage booster 107 is applied to the configuration of the air conditioner 100 of the third embodiment will be described.

As shown in Fig. 19, the present embodiment has a configuration in which the DC voltage boosting device 107 is connected to the motor driving device 106. Fig. On the other hand, the other configuration is the same as that of the air conditioner 100 of the first embodiment, and a description thereof will be omitted.

Here, with reference to Fig. 20, the efficiency of the compressor drive motor 105 of this embodiment and the dc voltage / applied voltage command will be described. 20 (a) shows the efficiency of the compressor drive motor 105. In Fig. 20 (b) shows amplitude values of the DC voltage and the applied voltage command.

As described in the first embodiment, in the voltage saturation region in which the amplitude value of the applied voltage command exceeds the DC voltage, the amplitude of the applied voltage command can not be controlled and the desired high voltage component 9A of the induced voltage from the power conversion circuit 4, Can not be output.

20 (b), the DC voltage supplied to the motor driving device 106 by the DC voltage booster 107 at the rotation speed N9 or more at which the voltage saturation region starts Up. Accordingly, even if the number of revolutions is N9 or more, the applied voltage command amplitude value can be controlled, and the desired high voltage component 9A of the induced voltage can be outputted from the power conversion circuit 4. [

According to the configuration of the third embodiment, the output of the organic voltage higher-order component 9A is also performed in the region where the output from the organic voltage higher-level component generator 9 is stopped in the first embodiment, It is possible to suppress the high-order component of the motor current caused by the distortion. Therefore, it is possible to reduce the loss of the motor drive device 106 and to achieve high efficiency of the air conditioner.

On the other hand, the present invention is not limited to the first to third embodiments, but includes various modifications. For example, the above-described embodiments have been described in detail in order to facilitate understanding of the present invention and are not limited to those having all the configurations described above.

It is also possible to replace part of the constitution of any embodiment with the constitution of another embodiment, and it is also possible to add the constitution of another embodiment to the constitution of any embodiment.

Further, it is possible to add, delete, and replace other configurations with respect to some of the configurations of the embodiments.

Further, the components, the functions, the processing units, the processing means, and the like may be realized by hardware by designing a part or all of them with, for example, an integrated circuit.

In addition, the control lines and information lines are considered to be necessary for explanation, and it is not necessarily the case that all the control lines and information lines are shown on the product. In practice, almost all configurations may be considered to be interconnected.

As described above, the motor drive apparatus of the present invention comprises: a power converter for supplying power to a permanent magnet motor; a control device for controlling an output voltage of the power converter; The higher the number of revolutions of the permanent magnet motor, the smaller the degree of the higher-order component of the induced voltage added to the voltage command value of the control device. According to the present invention, it is possible to prevent a situation in which a high-order component can not be outputted and the current waveform is distorted inversely.

The motor control device of the present invention further includes a power converter for supplying electric power to the permanent magnet motor, a control device for controlling the output voltage of the power converter, and a voltage adding device for adding a higher- The higher the number of revolutions of the permanent magnet motor, the higher the PWM frequency of the permanent magnet motor. According to the present invention, by suppressing the decrease in the number of PWM pulses included in one cycle of current due to the increase in the number of revolutions, the output of the higher-order component becomes possible.

The motor control apparatus of the present invention further includes a boosting circuit for boosting the DC voltage of the DC power supply. When the amplitude value of the output voltage is higher than the DC voltage, the boosting circuit boosts the DC voltage to an amplitude value or more of the output voltage .

The motor control device of the present invention is a motor control device for generating an induced voltage that generates a higher-order component of an induced voltage from higher-order component data of an induced voltage in accordance with the number of revolutions of the permanent magnet motor, the output torque of the permanent magnet motor, And a higher-order component generator, and adds the higher-order component of the induced voltage to the voltage command value of the controller. According to the present invention, the distortion of the current waveform due to the distortion of the induced voltage can be suppressed with a simple structure.

Further, the air conditioner of the present invention includes a compressor having a permanent magnet motor controlled by a controller, a condenser, an expansion device, and an evaporator.

1: Motor control device
2: DC power source
3: Permanent magnet synchronous motor
4: Power conversion circuit
5: DC bus current detection circuit
6: Control device
7: PWM pulse generating section
8:
9: Organic voltage high-order component generating unit
10:
41: Power conversion main circuit
42: gate driver

Claims (5)

A power converter for supplying power to the permanent magnet motor,
A control device for controlling an output voltage of the power converter,
And a voltage adding unit for adding a harmonic component of an induced voltage of the permanent magnet motor to a voltage command value of the control device,
Wherein the higher the number of revolutions of the permanent magnet motor, the smaller the order of harmonic components of the induced voltage added to the voltage command value of the control device. A power converter for supplying power to the permanent magnet motor,
A control device for controlling an output voltage of the power converter,
And a voltage adding unit for adding a harmonic component of an induced voltage of the permanent magnet motor to a voltage command value of the control device,
Wherein the higher the number of revolutions of the permanent magnet motor, the higher the PWM frequency of the permanent magnet motor. 3. The method according to claim 1 or 2,
And a step-up circuit for stepping up the DC voltage of the DC power supply,
Wherein when the amplitude value of the output voltage is higher than the DC voltage, the step-up circuit raises the DC voltage to an amplitude value or more of the output voltage. 3. The method according to claim 1 or 2,
And an organic voltage harmonic component generator for generating a harmonic component of the induced voltage from the harmonic component data of the induced voltage according to the rotational speed of the permanent magnet motor, the output torque of the permanent magnet motor, or the direct current bus current of the power converter,
And adds the harmonic component of the induced voltage to the voltage command value of the control device. An air conditioner comprising: a compressor having the permanent magnet motor controlled by the motor control device according to claim 1 or 2; a condenser; an expansion device; and an evaporator.

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